I just did the cat adapter. Its nice but kinda a pain in the @$$. Make sure you remove the check ball and use the cat filter only. I didnt use cats filter and found out that you need a different oring to seal it or it drops head pressure. The filter sticks to the adapter when changeing it and dont pay fot the spacer just get longer bolts and two nuts to fit over the bolts for spacers. Also you cant drain the water from the filter unless you remove the filter.